WASHINGTON, Feb 5 (Reuters) - The first major U.S.immigration reform effort since 1986 came under attack onTuesday from congressional Republicans who cast doubt on aproposal backed by President Barack Obama to give 11 millionillegal immigrants a chance to become citizens.

An immigration overhaul suddenly looked possible last weekwhen a group of senators from both parties launched a reformcampaign. But it has not taken long for partisan rancor toemerge.

Republicans in the House of Representatives are questioninga core element of the immigration plan: a path to citizenshipfor undocumented residents, most of them Hispanic, who arealready in the United States.

Bob Goodlatte, Republican chairman of the JudiciaryCommittee, raised the possibility of a "middle ground" betweenthe current U.S. policy of deporting illegals and of placingthem on a path to citizenship, as Obama demands.

"Are there options to consider between the extremes of massdeportation and pathway to citizenship?" the Virginia lawmakerasked during a session on immigration reform.

Any challenge to the Democrats' goal of providing a route tocitizenship might derail reform at a time when other divisiveissues like gun control and deficit reduction share thelegislative agenda.

Some House Republicans are wary of a repeat of the last bigimmigration push in 1986, when about 3 million illegalimmigrants were granted legal status.

At the time, proponents of the overhaul said it would stemthe flow of undocumented people across the Mexican border. Butillegal immigration just got worse.

"We look at the promises of the 1986 immigration reform whenwe granted citizenship to so many people, that we were going toseal the border and make sure this was a one-time deal ... andwe see that that has failed," Republican Blake Farenthold ofTexas told the Judiciary Committee.

"My question to you is: How do we not end up in the samesituation 10, 20 years down the road if we do this again?" heasked San Antonio Mayor Julian Castro, a rising Hispanic star inthe Democratic Party and a witness at the immigration hearing.

Senate Republicans who favor citizenship for illegalimmigrants under the bipartisan outline want to defer it untilthe country's borders are deemed more secure by a commission ofborder governors and other officials.

Democratic senators involved in the bipartisan group that isdrafting an immigration bill also approve of a border security"trigger."

But immigration reform activists asked Obama at a WhiteHouse meeting to stick to his position that 11 million peopleshould not have to wait until the border is declared secure.

"It can't be a trigger that keeps moving the goal posts andis indefinable. So it has to be meaningful, real and tangiblefor us to accept it," said Janet Murguia, president of theHispanic group National Council of La Raza.

The Obama administration points to a steep drop in illegalimmigration from Mexico in recent years and the deployment ofthousands of Border Patrol officers as evidence that the borderis more secure.

Spokesman Jay Carney said the White House had already metmany of the Republican criteria for border security.

"Close to all of those goals, if not all of those goals,have been met because of the president's commitment to enhancedborder security," he said.

Congressional Republicans have become more willing to workon an immigration reform after Hispanics delivered a clearmessage in the 2012 election. Seventy-one percent of Latinosvoted for Obama, compared to 27 percent for his Republican rivalMitt Romney.

He was vilified by many Hispanics for calling on illegalimmigrants to "self-deport."

REPUBLICAN REVERSAL?

In a speech billed as a move to present a softer image ofHouse Republicans, Majority Leader Eric Cantor of Virginia onTuesday expressed an eagerness to help the needy in such areasas immigration.

Cantor told the conservative American Enterprise Institutehe favored providing "an opportunity for legal residence andcitizenship for those who were brought to this country aschildren and who know no other home."

That appeared to represent a reversal for Cantor, who in2010 voted against the Dream Act, which would have cleared theway for such young people to remain in the United States.

Last summer Obama gave a temporary reprieve from deportationto qualifying children who came to the United States with theirparents.

Late on Tuesday, the president met with chief executivesfrom 12 companies on immigration reform and other issues,including Goldman Sachs Group Inc's Lloyd Blankfein,Yahoo Inc's Marissa Mayer as well as Arne Sorenson ofMarriott International Inc, Jeff Smisek of UnitedContinental Holdings Inc, and Klaus Kleinfeld of AlcoaInc.

Obama is expected to use his Feb. 12 State of the Unionspeech to Congress - a major annual address by the president inwhich he lays out his legislative priorities for the year - tokeep the heat on Republicans.